When Liverpool blew away runaway leaders Manchester City at Anfield in January, it seemed to vindicate the curious decision to cash in on Philippe Coutinho halfway through the season.
This it did, not just by virtue of the impressive result, but the very nature of the performance. As a representation of all that popular manager Jurgen Klopp stands for, it was definitive: a relentless, hungry side all pulling in one direction – the City goal.
It was a similar story on Tuesday evening as the Reds put FC Porto to the sword, winning 5-0 away in the first leg of their Champions League clash to all but secure their spot in the quarter-finals.
There was logically no place within either paradigm for the mercurial Brazilian, who had made clear his desire to leave, both last summer and again in the winter window.
This underscores one of the core requirements of 'Klopp-ball', which is a complete physical and emotional buy-in, not just from players and the fans, but from the man himself, often cartoonishly animated on the touchline. It makes Anfield a fortress, a seething cauldron from which few visiting sides emerge with fond memories.
However, that sense of a new dawn was slightly dampened by subsequent debacles against Swansea and West Bromwich Albion, as well as the draw against Tottenham, and it's why people shouldn't get too carried away by the Porto victory.
These struggles magnified the midfield void created by Coutinho's departure; but it also made clear quite why the Merseyside Reds were so keen to bring forward the arrival of midfielder Naby Keita.
Liverpool have since righted the ship and got back on track, but there is the sense that, for all that the progress made under Klopp is evident in the uniqueness and ferocity of the playing style, the German may be running out of learning curves. There is, after all, no trophy handed out for points against the rest of the top six.
There is only so long that the supporters can be content with the intangible.
It might seem an unpopular stat, but Klopp's win percentage (at 49.56) is weaker than his predecessor's: Brendan Rodgers (at 50.3), and even that is with the benefit of having played 54 fewer games. The Northern Irishman also favorably compares in the exhilaration stakes to his German counterpart, having taken Liverpool as close to a Premier League title as they have got since its inception in 1992.
Naby Keita | 2017-18 Bundesliga stats
For all that Klopp has set up to make sense, the puzzle will need to be completed soon. This is where Keita comes in; the Guinea international is not so much a Coutinho replacement as he is a vital piece of the jigsaw, and possibly the final one.
While Coutinho was vital for his flashes of inspiration, which could in part explain away his occasional positional flights of fancy, his inclusion in a midfield three, especially in a Liverpool side with no specialist defensive midfielder was often problematic. It could sometimes feel like shoehorning another forward into the side.
This is why acquiring Keita when they did was so important, and why trying to speed up the timeline was a legitimate desire. RB Leipzig, on their part, were vehement in their reluctance, even with reports indicating Liverpool were willing to pay a further £10 million.
Similarly, there were reports that the player was unsettled by the speculation, and that just ties in to that emotional buy-in, that state of hypnotic seduction that is necessary to play for Klopp. Even aside that, and beyond the fact that Liverpool so obviously need the 23-year-old, it is undeniable that Keita seems such a perfect player for Liverpool as well.
If the ideal of Klopp's midfield configuration is to eschew specialization and embrace all-rounders in aid of frenetic pressing, then it is almost impossible to find a better exemplar.
Keita's dynamism, proficiency both in defensive and offensive actions, and flair on the ball means he is tailor-made for Liverpool's style.
With his publicly stated desire to emulate legend Yaya Toure, coming to the Premier League is only the first step.
He will need to match the Ivoirian's transformative influence, or course, as well as carry the team to the silverware that is arguably needed to validate Klopp's Liverpool tenure.
More than anything else, it is this total intersection of need that makes it so perfect. Keita is the man to complete the cycle.